Soft Nanocomposite Based Multi-point, Multi-directional Strain Mapping Sensor Using Anisotropic Electrical Impedance Tomography

Abstract

The practical utilization of soft nanocomposites as a strain mapping sensor in tactile sensors and artificial skins requires robustness for various contact conditions as well as low-cost fabrication process for large three dimensional surfaces. In this work, we propose a multi-point and multi-directional strain mapping sensor based on multiwall carbon nanotube (MWCNT)-silicone elastomer nanocomposites and anisotropic electrical impedance tomography (aEIT). Based on the anisotropic resistivity of the sensor, aEIT technique can reconstruct anisotropic resistivity distributions using electrodes around the sensor boundary. This strain mapping sensor successfully estimated stretch displacements (error of 0.54 ± 0.53 mm), surface normal forces (error of 0.61 ± 0.62 N), and multi-point contact locations (error of 1.88 ± 0.95 mm in 30 mm × 30 mm area for a planar shaped sensor and error of 4.80 ± 3.05 mm in 40 mm × 110 mm area for a three dimensional contoured sensor). In addition, the direction of lateral stretch was also identified by reconstructing anisotropic distributions of electrical resistivity. Finally, a soft human-machine interface device was demonstrated as a practical application of the developed sensor.

A Sensorized Multicurved Robot Finger With Data-Driven Touch Sensing via Overlapping Light Signals

“…Extracting contact information from overlapping signals has been done in the context of methods inspired by Electric Impedance Tomography (EIT) [31]- [34]; for a comprehensive survey on the use of EIT for robotic skin see the work of Silvera et al [35]. EIT offers stretchable, continuous tactile sensing with the ability to discriminate multiple points of contact.…”

Enhanced sensing of gas molecules by a 99.9% semiconducting carbon nanotube-based field-effect transistor sensor

“…[http://dx.doi.org/10.1063/1.4991970] As transparent, conductive, and flexible materials, carbon nanotubes (CNTs) have attracted considerable attention for applications in several areas because of their many outstanding properties, including excellent electrical, mechanical, chemical, optical, and thermal properties. [1][2][3][4][5][6][7][8][9] Specifically, these properties render them promising candidates in broad areas of electronic applications. For example, CNTs have been considered an ideal material for gas sensing due to their intrinsically high surface-to-volume ratio originating from their nanosized, one-dimensional structure.…”

Toward Perceptive Soft Robots: Progress and Challenges

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